Eloeophila dietziana

Eloeophila dietziana (Alexander, 1925)

(Figs 4A–G, 13B)

Limnophila (Ephelia) dietziana Alexander, 1925: 437.

Type locality: Japan, Honshu, Kanagawa, Mt. Hakone-yama.

Limnophila (Ephelia) dietziana: Alexander (1930: 507); Alexander (1931: 340).

Limnophila (Elaeophila) dietziana: Alexander (1953: 167).

Eloeophila (s.str.) dietziana: Savchenko & Krivolutskaya (1976: 61).

Eloeophila dietziana: Nakamura (2014: 12); Oosterbroek (2021).

Material examined. HOLOTYPE male, JAPAN, Honshu, Sagami-no-kuni, Mt. Hakone, altitude 2,300 feet, 13.VII.1923, T. Esaki (USNM). Non-type material: JAPAN: [Honshu] 1 male, Aomori, Azigasawa-machi, Hitotsumori-machi, Sanai-zawa River, 2.VIII.2015, D. Kato (BLKU); 2 males, Aomori, Nakadomari-machi, Kodomari, 28.VII.2013, D. Kato (BLKU); 1 male, Yamanashi, Hokuto-shi, Mukawa-chô-Mifuki, Kamanashi-gawa River, Alt. 485 m, 14.VIII.2016, D. Kato (BLKU); 1 male, Echigo (Niigata), Kurokawa, 15.VIII.1954, K. Baba (USNM); 1 male, Gifu, Japanese Alps, Hirayu, 27.VII.1929, J. Machida (USNM). 1 male, Hida (Gifu), Akigami, Ontake, 20.VII.1960, Mishima (USNM); 1 male, Mino (Gifu), Neo, 2.VII.1957, T. Mishima (USNM); 1 male, Yamaguchi, Tokusa, 8.VII.1922, T. Shiraki (USNM); [Kyushu] 1 male, Mt. Kirishima, 2500 ft., 3. V.1929, S. Issiki (USNM); [Nansei Islands] Yakushima Is: 1 male, Miyanoura, near Sen-no-Ie, Alt. 20 m, 25.IV.2016, D. Kato (BLKU); Ishigaki Is: 1 male, Hirae, south of Nagura Dam, Alt. 80 m, 30.I.2018, D. Kato (BLKU).

Short description. General coloration grey and dark brown (Fig. 4A). Head. Grey to greyish ocherous with dark central stripe on vertex and dark lateral area on posterior part of vertex. Antenna about twice as long as head. Scape and pedicel dark brownish grey. Flagellum dusky yellow.

Thorax. Grey to greyish ocherous. Notum and pleuron mottled with dark brown spots and stripes. Wing (Fig. 4B) subhyaline, heavily patterned with numerous small spots in cells and large markings. Legs mainly yellow; each femur with dark band at tip, 4–5 times as long as wide. Halter pale yellow; knob dark brown.

Abdomen. Brown; pregenital segments weakly dark on posterior part of each segment. Male terminalia (Figs 4C–G) with outer gonostylus strongly narrowed on distal 1/4 into strongly curved, claw-shaped lobe, with subapical lobe at outer margin; apical inner edge angulated at almost right angle with rounded corner (Fig. 4D). Paramere with mesal-apical lobe blade-shaped, subacute at tip, about four times as long as wide and 1.5 times as long as lateral lobe (Fig. 4G). Aedeagus about six times as long as wide in lateral view, curved near middle and directed posteriorly on distal part (Fig. 4F). Apodeme of vesica directed ventrally (Fig. 4F).

Measurements. Male (n = 6): body length: 4.0– 4.8 mm; wing length: 5.0– 5.8 mm.

Distribution. Japan (Honshu, Shikoku, Kyushu, and Nansei Islands) and Kuril Islands (Kunashir Is) (Fig. 13B).

Remarks. This species resembles two Chinese species, E. similissima (Alexander, 1941) and E. suensoni (Alexander, 1926), but is differentiated from them by the following characters: flagellomeres on intermediate segments yellowish, not bicolorous (bicolorous, base of each segment slightly darkened in E. suensoni); each femur with dark band at tip (slightly pale at extreme tips of dark band in E. suensoni; outer face of dark band close to tips more reddish in E. similissima); outer gonostylus with distal claw-shaped part strongly curved, gradually narrow to tip (Fig. 4D) (slightly curved, gradually narrow to tip in E. suensoni; slender and strongly curved, middle part almost same in width in E. similissima).